Weed Potential
As a weedPaterson's Curse is wide spread in many agricultural regions of Australia and is highly invasive preferring a warm temperate climate with winter rainfall and appears in paddocks or disturbed soils or along roadways and invades woodlands, dry sclerophyll forests and low land grasslands.

This biennial has a fast growth rate forming a leafy rosette and erect stems with profuse flowering and seed production. It can produce up to 30,000 seeds per square metre and germinate readily producing a tap root up to 40 mm (1? in) long and quickly cover pastures smothering existing vegetation and covers an estimated 82 million acres in Australia.

Under drought conditions it has been used as fodder for grazing sheep but care must be taken as the plant contains poisonous alkaloids that accumulate in the liver and can cause death.

The seeds may remain dormant for up to 6-years but normally germinate within 2-years and are dispersed by attaching to clothing or wool or by a water run-off. In Australia it has adapted to the climatic conditions and may appear throughout the year.

Control methodsinclude physically digging out small infestations including the tap roots and the flowering stems and seed heads which are then burnt or destroyed. Larger infestations can be controlled by heavy grazing before the flowers appear or sprayed with herbicide during autumn or spring.

Small infestations have also been reported in California and western Oregon but have been contained and eradicated due to their limited distribution.